The biceps brachii of the shoulder

The biceps brachialis muscle , m. Biceps brachii, consists of two heads, round in shape, spindle-shaped. It occupies the anterior region of the shoulder and elbow fold and is located directly under the skin.

The long head, caput longum, occupies the lateral position. It begins as a long tendon from the superarticular tubercle of the scapula, passes over the head of the humerus through the cavity of the shoulder joint, lies in the inter-tubular furrow surrounded by the inter-tubercular synovial vagina, vagina synovialis intertubercularis, and then passes into the muscular abdomen.

The structure of the biceps arm muscle.

A short head, a caput breve, occupies a medial position. It begins with a wide sinew from the apex of the coracoid scapula and, going downwards, also passes into the muscular abdomen.

Both heads are connected to each other in a long muscular abdomen, which at the ulnar fossa narrows and turns into a powerful tendon, attached to the tuberosity of the radius. At the attachment point of the tendon is a double-headed bag, bursa bicipitoradialis, and between the tendons of the biceps and humerus muscles, at the top of the oblique chord, where it approaches the medial surface of the ulna, lies the interosseous ulnar bag, bursa cubitalis interossea.

From the proximal end of the tendon, a part of the bundles in the form of a thin plate is separated - the aponeurosis of the biceps arm muscle, aponeurosis m. Bicipitis brachii. On the sides of m. Biceps brachii on the shoulder are located medially and laterally almost symmetrically the furrows of the shoulder, sulcus bicipitalis medialis i sulcus bicipitalis lateralis.

Function: flexes the arm at the elbow joint and suppures the forearm; Due to the long head takes part in the lead of the hand, at the expense of the short one - in bringing the hand.

Innervation: n. Musculocutaneus (CV - CVII).

Blood-shed: aa. Collaterales ulnares superior et inferior, a. Recurrens radialis, a. Brachialis.